Method of manufacturing non-magnetic, elastic articles having a small change of vibration and deflection for temperature change



March 19, 1968 HAKARU MASUMOTO ETAL 3,374,123

METHOD OF MANUFACTURING NONMAGNETIC, ELASTIC ARTICLES HAVING A SMALLCHANGE OF VIBRATION AND DEFLECTION FOR TEMPERATURE CHANGE C5Sheets-Sheet 1 Filed March 5, 1965 mmm4mwmmm Fig.

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b---96% cold-waged state c--stute after heotin so le b at 560C for l5 h02 INVENTORS ATTORNEY 3,374,123 TIC, ELASTIC ARTICLES F VIBRATION ANDERATURE CHANGE March 19. 1968 HAKARU MASUMOTO ETAL METHOD OFMANUFACTURING NONMAGNE HAVING A SMALL CHANGE O DEFLECTION FOR TEMP 5Sheets-Sheet 2 Filed March 5, 1965 O v A O 2 w 8 .WW I 5 4 4 8 u M A...A I 7 2 I M M am. Q a 5 5 Q I N H -00 I A v 2 .m F w 0 ow .I A o 0 w 0 w0 m 0 Q Q a ABY JAM-$2M ATTORNEY March 1968 HAKARU MASUMOTO ETAL'3,374,123

METHOD OF MANUFACTURING NONMAGNETIC, ELASTIC ARTICLES HAVING A SMALLCHANGE OF VIBRATION AND DEFLECTION FOR TEMPERATURE CHANGE Filed March 3,1965 6 Sheets-Sheet 5 Fig.3.

Pd48%, Au 52% Pa 546.0- 3 3 545.0 5' 526.0- g Pd52k,Au48% g 0 I0 so 40so so Temperature ('6) Z INVENTORS m/mez/ MASUMfiTO 74 A/EO K054 V4860BY JM M ATTORNEY United States Patent 3,374,123 .METHOD OF MANUFACTURINGNON-MAG- N ETIC, ELASTIC ARTICLES HAVING A SMALL CHANGE OF VIBRATION ANDDE- FLECTION F R TEMPERATURE CHANGE Hakaru Masumoto, Sendai, and TakeoKobayashi, Natori,

Japan, assignors to The Foundation, The Research Institute of Electricand Magnetic Alloys, Sendai, Japan Filed Mar. 3, 1965, Ser. No. 436,902laims priority, application Japan, Mar. 4, 1964,

39/ 11,779 3 Claims. (Cl. 148-11.5)

ABSTRACT OF THE DISCLOSURE A method of manufacturing non-magneticandelastic 7 articles having little change in Youngs modulus with change intemperature, which comprises annealing an alloy consisting essentiallyof about 50% gold and about 50% palladium by heating said alloy at atemperature above 600 C. for at least one minute, and then heat treatingsaid alloy by a suitable combination of quenching, cold working, andtempering.

In conventional methods of manufacturing elastic articles having a-smalltemperature change of vibration and deflection, elinvar type alloys(Fe-Ni alloys added with other elements) and co-elinvar type alloys(Fe-Co alloys added with other elements) have been used.

All the above known alloys, however, show not only ferromagneticproperties but also' have disadvantage of causing corrosions whenexposed to, an acidic or alkaline vapour or solution or to a solution ofsalts.-Accordingly,

hitherto conventional alloys are not suitable for certain applications.7 f

As a result of a number of investigations and experiments to obviatethe. above disadvantage of conventional alloys, the-inventors discoveredthat palladium-gold-alloys sion but also non-magnetic properties as wellas-a hardness of 'various degrees- Alloys of the invention obviate thedisadvantage'inherentto conventional elastic alloys.

. A process of manufacturing the elastic articles accordand about 50% byweight of goldis subjected to one of .ing to the invention ischaracterized in that a binary alloy consisting essentially of about byweight of palladium is quenched by rapidly cooling it at a rate fasterthan 1 C./second andthen heated at a comparatively low temperature, suchas 200 to 550 C.;

(2)An a'l'loytannealed'ata temperature above 600. C.

is cold worked to reduce the sectional area more'than 20% at roomtemperature and then heated at a:com-

paratively low temperature, 'such as 200'to 550 C.;

(3)An alloy annealed at a temperature above 600 C.

is first'qu'enched by rapidly cooling it at a rate faster 3,374,123Patented Mar. 19, 1968 lastly heated at a comparatively low temperature,such as 200 to 550 C. The article thus obtained has an arbitrary valueof temperature coefficient of Youngs modulus (or rigidity modulus)ranging from an ordinary negative value to a positive value anddifferent values of hardness.

' The principles of the invention will now be explained further indetail. According to the invention, at first, a mixture consisting of aproper amount of palladium and gold or in addition suitable amount ofsaid sub-ingredients is melted in air, in vacuo, or in an inert gas bymeans of a suitable furnace, then degassed by adding a small quantity ofdegassing agent (element) such as manganese, silicon aluminum, titanium,etc., and stirred thoroughly to produce a melted alloy havinghomogeneous structure. Then the melted alloy is poured into a mould ofsuitable size and shape to obtain a sound ingot, and the ingot thusprepared can be forged, rolled, swaged or drawn at room tempreature orat an elevated temperature lower than 1400 C. to provide a producthaving desired shape and size.

Thereafter, the product is heated for more than 1 minute, say 1 hour, ata temperature higher than 600 C.

but lower than the melting point of the alloy and then gradually cooled.If desired, the mechanical strength of the product can be increased byseveral means for instance by quenching from a temperature higher than400 C. but lower than the melting point of the alloy or by cold workingat a reduction ratio more than about 20% or by applying both quenchingand cold working. If further stabilizationof characteristics is desired,the product can be heated at a temperature higher than 200 C. but

lower than 550 C. for at least one minute after the above quenching orcold working or application of both quenching and cold working. Thefinal product thus obtained shows an arbitrary value of temperaturecoefiicient of Youngs modulus (or rigidity modulus) ranging from 'anordinary negative value to a positive value.

v For a better understanding of the invention reference is made to theaccompanying drawings,.in which FIG. 1 is a diagram illustratingdensities (at 20 C.),

.Youngs moduli (at 20 C.), mean temperature coeffi- ,cients (0-40 C.) ofYoungs modulus (040 C.) and mean thermal expansion coeficients (0-40 C.)of palladium-gold alloys for different concentration of palladium insaidalloys;

FIG. 2 is a diagram illustrating mean temperature coefficients of Youngsmodulus (040 C.) of three kinds of alloys which were processed throughcold swaging at a reduction ratio of 96%, for different annealing term50 have not only-high resistances against oxidation and corrofirstmelted in an alumina crucible of about 10; mm.

inside dia. by means of a Tammann furnace (electric resistance furnace)while passing hydrogen gas, then the mixture was stirred thoroughly andcooled in said crucible.

Then the ingot Was'made into a bar of about 2 mm. dia.

by swaging at a reduction ratio of 96% at room temperature, and aportion of the bar, about 10 cm. long, was cut offto provide a sample todetermine-behaviours in the state -of cold working. The sample was thenheated at various temperatures for 15 hours and cooled to takemeasurements. At last, the sample was annealed at 1000" C. for one hourand then measurements were made.

.Youngs .moduli were determined by measuring at first naturalfrequencies of the sample bars by means of a device, based on principlesof an electrostatic vibrator controlled oscillator, and then bycalculation from the ditions, that is to say the conditions when thesample bars being gradually cooled at a rate of 300 C. per hour afterheated at 1000 C. for one hour. The curve b indicates the values forconditions after processed through cold swaging at a reduction ratio of96%, and the curve for conditions after heating the sample bars of thecurve b at 360 C. for 15 hours.

FIG. 2 illustrates how the mean temperature coefficients of Youngsmodulus in the range of 0 to 40 C. vary for the different annealingtemperatures. FIG. 3 illustrates how natural frequencies of three kindsof Pd-Au alloys annealed at 360 C. for 15 hours following cold workingvary for different measuring temperatures.

As shown in FIG. 1, the temperature coefficients of Youngs modulus ofannealed alloys consisting essentially of 30 to 70% of palladium and 70to 30% of gold lie within a range of from 18.0 10- to 3.0 when thetemperature of the alloy is in the neighbourhood of room temperature,especially said coefficient of the alloys consisting essentially of 57to 37% of palladium and 43 to 63% of gold is substantially small.

As shown in FIG. 1, the temperature coefiicients of Youngs modulus ofalloys of the invention after processed through cold working are largerin negative domain than those of said alloys under annealed conditions,however, when said cold worked samples are annealed once again at atemperature approximately 360 C. for hours the negative values of saidcoefficients are substantially reduced, especially said coefficient ofthe alloy consisting essentially of 50% of palladium and 50% of goldbecomes +2.8 10 Besides, after the additional annealing. following coldworking, the natural frequencies of the alloys of the present inventionvary in a substantially linear relationship with temperatures as shownin FIG. 3

aslong as the temperature lies in the neighbourhood of room temperature,which is also a salient feature of the alloys of the invention comparedwith conventional elinvar type alloys showing a considerable non-linearvariation of characteristic frequencies when temperature varies in theneighbourhood of room temperature (see FIG. 3).

The alloys of the invention are also characterized in havingnon-magnetic properties. Non-magnetic materials having constant valuesof Youngs modulus for the temperature change have never been inventedheretofore, and the alloys of the present invention are the first of thekind. In addition, the alloys of the invention have substantially strongresistances against oxidation and corrosion. I Elfects of thesub-ingredients on the properties of pal ladium-gold alloys are shown inTable 1. It is apparent from Table 1 that additions of other elementsinto palladium-gold alloys generally result in a substantial increase inhardness both under the annealed condition and under the condition whenheated at 360 C. following cold swaging, irrespective of the fact thatthe temperature coefficients of Youngs modulus are caused to increase inthe negative domain by said additions. The increase in hardness meansthe increase in yield point, which is very preferable for application ofthe alloys to springs Itcan be emphasized here that applicationofquenching from an elevated temperature or, a combination of TABLE 1 Asannealed As heated at 360 C.

at 1,000C.' for 15 hrs. after [or 1 hour 96% cold-reduction Alloys, 50%5 1 150% Au alloy Temperature Micro- Temperature MicrocoeliicientVickers coeflicient Vlekers of Youngs hardness of Youngs hardnessmodulus (20 0.), 89 modulus (20 0.), 184 I (040 0.), (040 C Atoresaidalloy 21th addition 3. 0% PL... 9. 8 116 7. 5 212 1. 0% 111.... 11. 0138 4. 7 249 3. 0% In- 11. 5 100 9. 9 245 3. 0% Ta. 13. 1 128 9. 3 2583. 0% Ag 10. 5 100 9. 5 210 3. 0% Fe. 15. 0 126 10. 2 278 3.0 0 Ni. -14.0 144 6. 7 268 3. 0 0 00.... 11. 1 123 9.9 273 1.0% CL..- 13. 5 101 11.2260 3.0 0 Mn... 10.0 112 8.0 212 3.0% Cu... 11.0 93 7.3 241 1.0 V...10.0 118 7.3 269 3.0% Mo--. 13.0 143 8. 5 291 3. 0% W 14.0 134 11. 0 2630.2% 14.0 127 9. 8 277 3. 0% 8. 0 124 5. 5 289 3. 0% 13. 0 107 --5. 6261 3. 0% -13. 5 109 6. 5 242 0.2% T1 11.0 122 6.0 248 0. 17 10. 0 1326. 7 267 1. 0%; 9. 0 140 7. 4 233 0. 5% 14. 7 128 -11. 1 267 0.5% 11.0117 6.0 250 0.1% -15. 5 112 --11.0 216 1. 0% -15.0 105 5. 4 216 As shownin the foregoing descriptions, temperature coefficients of Youngsmodulus of the alloys of the invention are not only small but alsopractically constant at different temperatures in the neighbourhood ofroom tempcrature. Furthermore, the alloys of the invention havenonmagnetic properties and substantially high resistances againstoxidation and corrosion. Therefore, the alloys of the invention are mostsuitable to devices which require constant frequencies regardless ofambient temperature variation and non-magnetic 1 properties, such ashair springs of chronometers, standard tuning forks, etc.

In order to obtain a sound ingot, better forgeability and bettermechanical properties of materials according to the invention, thealloys consisting essentially of palladium and gold can be added with 0to 3% of one or more elements selected from the group consisting ofplatinum, iridium, indium, tantalum, silver, iron, nickel, cobalt,chromium, manganese, copper, vanadium, molybdenum, tungsten, aluminium,antimony, tin and zinc and 0 to 2% of more thanone elements selectedfrom the group consisting of titanium, silicon, cadmium, beryllium,zirconium, boron and niobium as sub-ingredients.

What we claim is:

'1. A method of manufacturing nonmagnetic and elastic articles havinglittle variation in Youngs modulus upon temperature change, comprisingthe steps of annealing a gold-palladium alloy consisting essentially ofabout 50% by weight of gold and about 50% by weight of palladium' byheating it at a temperature higher than 400 C.

but lower than themelting point of the alloy for more than one minute,quenching by cooling it at a rate faster than 1 C. per second, andtempering by further heating by heating it at a temperature higher than400 C. but lower than the melting point of the alloy for more than oneminute, then working it at room temperature to re- 5 6 duce itscross-sectional area by more than about 20%, OTHER REFERENCES andtempering by further heatmg It at a tempefamre The Platinum Metals andTheir Alloy s, Vines, 1941, pp. tween 200 C. and 550 C. for at least onemmute.

34-42, 110-112. References Cited 5 DAVID L C P E UNITED STATES PATENTS2,780,543 2/1957 Schneider et a1. 7s 172 SAITO Amid"! Exammer-

